Shut off valve

Abstract

A refuelling coupling having a shut off valve for a refuelling system has an annular member equipped with a connector for a pressure refuelling nozzle. A main sleeve extends down from the annular member within the skirt. The sleeve has an annular valve seat and a circular cylindrical distal end section. The seat has a conical face facing obliquely inwards and downwards. Below the valve seat, a plurality of peripherally arranged openings are provided in the end section. An end cap is screwed on across the very end of the lower portion, closing it with ports in the end cap. It also has an inner sleeve extending back up centrally to the level of the valve seat. The end cap is open inwards of the inner sleeve.

The invention claimed is: 
     
       1. A refuelling coupling having a shut off valve, the refuelling coupling comprising:
 an annular member, 
 a fitting on the annular member complementary to a pressure refuelling nozzle, 
 a displaceable dry-break member in the coupling for normally sealing the coupling via a seal between the annular member and the dry-break member, the dry-break member being displaceable from its sealing position on connection of a pressure refuelling nozzle, and 
 a primary sleeve extending from the annular member to provide a pressure flow passage for receiving pressurised fuel with the dry-break member displaced into the upstream end of the pressure flow passage, the primary sleeve having: 
 peripheral openings at a downstream end of the sleeve for dispensing of the pressurised fuel flowing from the flow passage; 
 the shut off valve comprising: 
 an annular seat carried on the primary sleeve on the upstream side of the openings, 
 an end cap of the sleeve having: 
 an inner sleeve extending back towards the annular member and defining with the primary sleeve an annular cylinder closed by the end cap, 
 an annular piston in the annular cylinder having: 
 one or more openings allowing passage of pressurised fuel from within the primary sleeve to the opposite side of the annular piston and 
 a formation complementary to the annular seat whereby pressurised fuel on the opposite side of the annular piston can co-operate with the annular seat and close the peripheral openings and 
 a float valve with at least one closable outlet in the end cap arranged to be closed for movement of the annular piston against the annular seat when refuelling is reaching completion to close flow communication from the pressure flow passage to the openings. 
 
     
     
       2. A refuelling coupling having a shut off valve according to  claim 1 , wherein the annular piston has an annular groove in its underside and inlets to the groove in its top side. 
     
     
       3. A refuelling coupling having a shut off valve according to  claim 2 , wherein the inlets are provided in at least one metering component, preferably a metering plate secured to the top side of the annular piston, the or each meter component having at least one aperture for arranged to provide a pressure drop in fuel flowing through it into a respective one of the inlets. 
     
     
       4. A refuelling coupling having a shut off valve according to  claim 1 , wherein the primary sleeve is a compound member having:
 an upper portion secured to the annular member and, 
 a lower portion having the annular seat. 
 
     
     
       5. A refuelling coupling having a shut off valve according to  claim 1 , wherein the annular seat is conical, facing obliquely inwards and downwards. 
     
     
       6. A refuelling coupling having a shut off valve according to  claim 1 , wherein the dry-break member is a plug urgeable to close the annular member and having:
 a secondary sleeve extending from the plug and within the primary sleeve, with the pressure flow passage therebetween, 
 an aperture in the displaceable dry-break member and 
 a subsidiary displaceable member carried by the dry-break member, this member normally closing the aperture and being displaceable by introduction of a gravity refuelling nozzle into the aperture and 
 the secondary sleeve slidably engages with the inner sleeve and 
 the end cap is open centrally, 
 the arrangement being such that a gravity refuel nozzle can be passed through the aperture in the dry-break member for gravity refuelling through the secondary sleeve. 
 
     
     
       7. A refuelling coupling having a shut off valve according to  claim 5 , wherein the secondary sleeve extends within the inner sleeve. 
     
     
       8. A refuelling coupling having a shut off valve according to  claim 6 , including springs for urging the plug into its closed position. 
     
     
       9. A refuelling coupling having a shut off valve according to  claim 8 , wherein the springs are carried on pins extending from the valve seat to the annular member and acting on a rim extending radially of the plug. 
     
     
       10. A refuelling coupling having a shut off valve according to  claim 5 , wherein the diameter of the secondary sleeve is smaller than that of a displacer on the pressure refuelling nozzle, nett pressure force on the dry break member is such as to urge the plug sealingly against the displacer. 
     
     
       11. A refuelling coupling having a shut off valve according to  claim 1 , wherein the float of the float valve is annular with a central opening aligned beneath the central opening of the end cap for unimpeded flow of gravity refuelling fuel. 
     
     
       12. A refuelling coupling having a shut off valve according to  claim 11 , wherein the annular float valve is pivoted to one side and provided with a closure member at the other side for closing the end cap outlet under the annular piston. 
     
     
       13. A refuelling coupling having a shut off valve according to  claim 11 , wherein the annular float has a plurality of closure members for closing a corresponding plurality of end cap outlets. 
     
     
       14. A refuelling coupling having a shut off valve according to  claim 13 , wherein the closure members have tips for closing the outlets. 
     
     
       15. A refuelling coupling having a shut off valve according to  claim 14 , wherein the float valve is provided with a corresponding plurality of pilot valve bodies having radial exhausts, each having a radial passage or an axial passage interruptible by a respective one of the closure members upstream of its radial exhaust. 
     
     
       16. A refuelling coupling having a shut off valve according to  claim 13 , wherein the closure members are arranged to have passage flow pressure applied under them in a piston and cylinder manner, to ensure valve closure. 
     
     
       17. A refuelling coupling having a shut off valve according to  claim 14 , including guide members fast with the end cap for engaging with a central opening in the annular float and guiding it in movement towards and away from the end cap. 
     
     
       18. A refuelling coupling having a shut off valve according to  claim 17 , wherein the guide members are tongues engaging complementarily with the central opening in the annular float and the links are provided, connected at one end to the guides, at the other end to the annular float and intermediately to the closure members.